Compactors are machines used to compact material, such as asphalt, soil, gravel, and the like to a dense surface. Various types of compactors are known in the art. Some compactors include a rotatable roller drum that may be rolled over the surface to compress the material underneath. In addition to utilizing the weight of the roller drum to provide the compressive forces that compact the material, some compactors are configured to also induce a vibratory force to the surface. The vibratory forces assist in compacting the surface into a dense mass.
To generate the vibratory forces one or more weights or masses may be disposed inside the roller drum at a position that is off center from the axis line around which the roller drum rotates. As the roller drum rotates, the position of the masses induce oscillatory or vibrational forces to the drum that are imparted to the surface being compacted.
U.S. Pat. No. 5,164,641 (the '641 Patent) issued Nov. 17, 1992 to Caterpillar Paving Products Inc. discloses an apparatus for controlling the frequency of vibration of a compacting machine. The accelerometer of the '641 Patent is mounted on a nonrotating element of the compactor drum. While this system is beneficial, an apparatus is desired in which a sensor such as an accelerometer may be mounted on an element of the drum that is moveable.